In the middle of a debate on "intolerance", former Prime Minister Manmohan Singh today said suppression of dissent poses "grave danger" for economic development.


"The nation is deeply concerned at recent tragic instances of violations of freedom of thought," he said at a conference organized to mark the 125th birth anniversary of Jawaharlal Nehru.


Dr Singh said no religion can become basis of public policy. "Religion is a private matter in which no one, including state, can interfere," he said, adding, "Secularism is an article of faith... it protects the fundamental freedom of every citizen."


The former prime minister's sharp comments come at a time "rising intolerance" has ignited a maelstrom of protests after incidents like the killing of rationalists and mob attacks over beef-eating or cow slaughter rumours.


"The nation is  deeply concerned at the recent tragic instances of blatant violations of the right to freedom of thought, belief, speech and expression in our country by some violent extremist groups. The assault or murder of thinkers cannot be justified on any grounds, nor can suppression of right to dissent be allowed," said Dr Singh.


"All right thinking people in the country have condemned such incidents in the strongest terms as an assault on the nation," he added.


Earlier this week, Dr Singh joined Congress president Sonia Gandhi and her son Rahul Gandhi in the Congress party's march to the President's House to flag concerns about what it calls an assault on freedom of speech.